Foaming resin composition, plastic foam formed from the composition, and method for forming the plastic foam

ABSTRACT

A foaming resin composition consisting essentially of (A) an organic compound having a carbon-carbon double bond, (B) a compound having an SiH group, and (C) a compound having an OH group is foamed and cured at room temperature or under heat at relatively low temperatures, to obtain hard, semi-hard or soft plastic foam having good weather resistance and good compatibility with coating compositions and adhesives.

BEST MODES OF CARRYING OUT THE INVENTION

Examples of the present invention are mentioned below along with acomparative example.

SYNTHESIS EXAMPLE 1

Polyoxypropylene having a number average molecular weight of 3,000 andsodium hydroxide were mixed at 60° C. and then reacted withbromochloromethane added thereto, whereby the molecular weight of thepolymer was increased. Next, allyl chloride was added to this andreacted at 110° C. Thus, the terminal of the polymer wasallyl-etherified. This was treated with aluminium silicate, and a pure,terminal-allyletherified polyoxypropylene was obtained.

The polyether had a number average molecular weight of 7,960, and themeasurement of its iodine value revealed that the polyether had anolefinic group at 92% of its terminal. The viscosity of the polyetherwas measured with an E-type viscometer to be 140 poises at 23° C.

SYNTHESIS EXAMPLES 2

Polyoxypropylene (of a triol type) having a number average molecularweight of 3,000 was allylated in the same manner as in Synthesis Example1 but without increasing its molecular weight. The degree of allylationof the polymer was 87 %. The viscosity of the polymer was 3.5 poises at23° C.

SYNTHESIS EXAMPLE 3

A one-liter, three-neck flask equipped with a stirring rod, a three waystop-cock and a condenser was prepared. 114 g of bisphenol A, 145 g ofpotassium carbonate, 140 g of allyl bromide and 250 ml of acetone wereput into the flask and stirred at 60° C. for 12 hours. The supernatantof the resulting mixture was taken out, washed with an aqueous solutionof sodium hydroxide, using a separating funnel, and then washed withwater. The oily layer was dried with sodium sulfate, and the solvent wasremoved therefrom, using an evaporator. Thus was obtained 126 g of apale-yellow liquid. Through its ¹ H-NMR, it was found that the productthus obtained is an allylated bisphenol resulting from theallyl-etherification of the OH group of bisphenol A. The yield of theproduct was 82% and the purity thereof was 95% or higher.

SYNTHESIS EXAMPLE 4

A one-liter, four-neck flask equipped with a stirring rod, a droppingfunnel, a condenser with a three way stop-cock at its top, and athermometer was prepared. 12.3 g of methylhydrogenpolysiloxane (KF-99,produced by Shin-etsu Chemical Co.) (200 mmols in terms of SiH group),11.5 g of benzothiazole, 60 μl of a solution of platinum-vinylsiloxanecomplex in xylene (5.0 ×10⁻³ mmols in terms of platinum atom), and 10 mlof toluene were put into the flask. The resulting mixture was heated at80° C., and a solution of 7.0 g of propylene oxide-ethylene oxidecopolymer that had been modified with a butyl group at one terminal andwith an allyl group at the other terminal (20 mmols in terms of vinylgroup), as dissolved in 80 ml of toluene, was dropwise added theretothrough the dropping funnel over a period of 2 hours. After theaddition, this was stirred still at 80° C. for 2 hours. After thedisappearance of the peak for the vinyl group in the reaction mixturewas confirmed through ¹ H-NMR, the mixture was cooled. 10 g of activecharcoal was added to this and stirred at room temperature for 1 hour.The resulting mixture was filtered, and the filtrate was concentrated.Thus was obtained a viscous liquid of polyether-modifiedmethylhydrogenpolysiloxane.

SYNTHESIS EXAMPLE 5

A one-liter, four-neck flask equipped with a stirring rod, a droppingfunnel, a condenser with a three way stop-cock at its top, and athermometer was prepared. 12.3 g of methylhydrogenpolysiloxane (KF-99,produced by Shin-etsu Chemical Co.) (200 mmols in terms of SiH group),11.5 g of benzothiazole, 60 μl of a solution of platinum-vinylsiloxanecomplex in xylene (5.0×10⁻³ mmols in terms of platinum atom), and 10 mlof toluene were put into the flask. The resulting mixture was heated at80° C., and a solution of 80.0 g of propylene oxide-ethylene oxidecopolymer that had been modified with a butyl group at one terminal andwith an allyl group at the other terminal (50 mmols in terms of vinylgroup), as dissolved in 80 ml of toluene, was dropwise added theretothrough the dropping funnel over a period of 2 hours. After theaddition, this was stirred still at 80° C. for 2 hours. After thedisappearance of the peak for the vinyl group in the reaction mixturewas confirmed through ¹ H-NMR, the mixture was cooled. 10 g of activecharcoal was added to this and stirred at room temperature for 1 hour.The resulting mixture was filtered, and the filtrate was concentrated.Thus was obtained a viscous liquid of polyether-modifiedmethylhydrogenpolysiloxane.

SYNTHESIS EXAMPLE 6

Synthesis of allylated, resol-type phenolic resin:

40 g of resol-type phenolic resin (PL-4567, produced by Gun-ei ChemicalCo.) (this is in the form of an aqueous solution having a solid contentof 75% by weight, and this has an OH content of 17.8 mmol/g) was putinto a four-neck flask equipped with a thermometer, a reflux condenser,a dropping funnel and a stirring motor, and 62.6 g of an aqueoussolution of NaOH (50% by weight) was gradually added thereto. This wasstirred at 50° C. for 1 hour, and 65.4 g of allyl chloride was dropwiseadded thereto and reacted at 44° C. for 3 hours. The salt was removedthrough filtration, and the filtrate was extracted with CH₂ Cl₂. Theextract was neutralized with hydrochloric acid and then washed withwater. This was dried with MgSO₄, and CH₂ Cl₂ was removed from thisthrough distillation. Thus was obtained 15 g of a product having anunsaturated group content of 8.0 mmol/g as determined through themeasurement of its iodine value.

SYNTHESIS EXAMPLE 7

Synthesis of O-allylated, novolak-type phenolic resin:

36.9 g of novolak-type phenolic resin (PSM4261, produced by Gun-eiChemical Co.--this has an OH content of 9.71 mmol/g) and 160 ml ofacetone were put into a four-neck flask equipped with a thermometer, areflux condenser, a dropping funnel and a stirring motor, and 50 g ofpotassium carbonate was added thereto while stirring. Next, 52 g ofallyl bromide was dropwise added thereto little by little and thenreacted at 55° C. for 6 hours. This was filtered, concentrated andwashed with an alkali and an acid in that order. 7.4 g of aluminiumsilicate was added thereto and stirred. This was filtered andconcentrated. Thus was obtained 40 g of a product having an unsaturatedgroup content of 7.3 mmol/g as determined through the measurement of itsiodine value. Through its ¹ H-NMR, it was found that the product is anO-allylated, novolak-type phenolic resin (of an allyl ether type)resulting from the allylation of the OH group in the starting resin.

SYNTHESIS EXAMPLE 8

Synthesis of C-allylated, novolak-type phenolic resin:

The allylated, novolak-type phenolic resin as obtained in SynthesisExample 7 was heated at 180° C. for 3 hours while stirring it in anitrogen atmosphere. Thus was obtained 40 g of a rearranged producthaving an unsaturated group content of 7.3 mmol/g as determined throughthe measurement of its iodine value. Through its ¹ H-NMR, it was foundthat the product is a C-allylated, novolak-type phenolic resin (of anallylphenol type) resulting from the Claisen rearrangement of the allylgroup in the starting resin.

Example 1

8.8 g of the allyletherified polyoxypropylene as produced in SynthesisExample 1 (2.0 mmols in terms of vinyl group), 0.63 g ofmethylhydrogenpolysiloxane (KF-99, produced by Shin-etsu Chemical Co.)(10.0 mmols in terms of SiH group), and 0.3 g of 1-propanol were mixedby stirring them. 24 μl of a solution of platinum-vinylsiloxane complexin xylene (2.0×10⁻³ mmols in terms of platinum atom) was added to theresulting mixture, stirred and injected into a rectangularparallelepiped container having a known capacity. This was kept thereinat 25° C. for 10 minutes and foamed to obtain a mass of soft plasticfoam. This was cut along the top of the container, and the weight of thepiece was measured to obtain its density. The expansion ratio of theproduct was obtained, on the basis of the density of the non-foamedmixture as obtained prior to the addition of the catalyst thereto, to beabout 10 times. The cross section of the piece was observed with anoptical microscope to examine the morphology of the cells therein, fromwhich it was found that the majority of the cross section had a uniformcellular structure comprising cells of from 0.2 to 0.5 mm in size. Thepercentage of the closed cells in the plastic foam was calculatedaccording to ASTM D-2856 to be 95%.

Example 2

The same components, allyletherified polyoxypropylene, 1-propanol andplatinum catalyst, as those in Example 1 were mixed in the same ratio asin Example 1 to prepare a liquid A. On the other hand, the samemethylhydrogenpolysiloxane as in Example 1 was prepared as a liquid B.The two liquids A and B were mixed in the same ratio as in Example 1 andjetted out onto a vertical concrete wall through a two-liquid jettingdevice. The liquid mixture thus jetted out was foamed on the surface ofthe wall to give a sheet of plastic foam thereon as in Example 1.

Example 3

8.8 g of the allyletherified polyoxypropylene as produced in SynthesisExample 2 (2.0 mmols in terms of vinyl group) , 1.1 g of thepolyether-modified methylhydrogenpolysiloxane as produced in SynthesisExample 4 (10.0 mmols in terms of SiH group), and 0.48 g of 1-propanolwere mixed by stirring them. 72 μl of a solution ofplatinum-vinylsiloxane complex in xylene (6.0×10⁻³ mmols in terms ofplatinum atom) was added to the resulting mixture and mixed, whereby themixture was foamed to give a mass of soft plastic foam. The expansionratio of the plastic foam was 10 times.

Example 4

2.2 g of the allylated bisphenol as produced in Synthesis Example 3(14.0 mmols in terms of vinyl group), 1.2 g of the polyether-modifiedmethylhydrogenpolysiloxane as produced in Synthesis Example 5 (2.0 mmolsin terms of SiH group), 1.1 g of methylhydrogenpolysiloxane (18.0 mmolsin terms of SiH), and 0.24 g of 1-propanol were mixed by stirring them.48 μl of the same platinum catalyst solution (4.0×10⁻³ retools in termsof platinum atom) as in Example 1 was added to the resulting mixture inthe same manner as in Example 1. Thus was obtained a mass of hardplastic foam. The expansion ratio of the plastic foam was 10 times.

Example 5

2.2 g of an allyl-bisphenol resulting from the allylation of bisphenol Aat its ortho-position (MATRIMID5292B, produced by Ciba-Geigy Co.) (14.0mmols in terms of vinyl group), 1.2 g of the polyether-modifiedmethylhydrogenpolysiloxane as produced in Synthesis Example 5 (2.0 mmolsin terms of SiH group), 1.1 g of methylhydrogenpolysiloxane (18.0 mmolsin terms of SiH group), and 0.24 g of 1-propanol were mixed by stirringthem. 48 μl of the same platinum catalyst solution (4.0×10⁻³ mmols interms of platinum atom) as in Example 1 was added to the resultingmixture in the same manner as in Example 1. Thus was obtained a mass ofhard plastic foam. The expansion ratio of the plastic foam was 15 times.

Example 6

2.2 g of an allyl-bisphenol resulting from the allylation of bisphenol Aat its ortho-position (2,2'(6')-diallyl-4,4'-isopropylidene-diphenol)(14.0 mmols in terms of vinyl group), 2.2 g of the polyether-modifiedmethylhydrogenpolysiloxane as produced in Synthesis Example 4 (20.0mmols in terms of SiH group), 0.18 g of 1-propanol, and 0.108 g ofdistilled water were mixed by stirring them. 48 μl of the same platinumcatalyst solution as in Example 1 was added to the resulting mixture inthe same manner as in Example 1. Thus was obtained a mass of hardplastic foam. The expansion ratio of the plastic foam was 10 times.

Example 7

1.75 g of allylated resol-type phenolic resin as produced in SynthesisExample 6 (14.0 mmols in terms of vinyl group), 2.2 g of thepolyether-modified methylhydrogenpolysiloxane as produced in SynthesisExample 4 (20.0 mmols in terms of SiH group), 0.18 g of 1-propanol, and0.108 g of distilled water were mixed by stirring them. 48 μl of thesame platinum catalyst solution as in Example 1 was added to theresulting mixture in the same manner as in Example 1. Thus was obtaineda mass of hard plastic foam. The expansion ratio of the plastic foam was10 times.

Example 8

1.92 g of the O-allylated, novolak-type phenolic resin as produced inSynthesis Example 7 (14.0 mmols in terms of vinyl groups), 2.2 g of thepolyether-modified methylhydrogenpolysiloxane as produced in SynthesisExample 4 (20.0 mmols in terms of SiH group), 0.18 g of 1-propanol, and0.108 g of distilled water were mixed by stirring them. 48 μl of thesame platinum catalyst solution as in Example 1 was added to theresulting mixture in the same manner as in Example 1. Thus was obtaineda mass of hard plastic foam. The expansion ratio of the plastic foam was8 times.

Example 9

1.92 g of the C-allylated, novolak-type phenolic resin as produced inSynthesis Example 8 (14.0 mmols in terms of vinyl groups), 2.2 g of thepolyether-modified methylhydrogenpolysiloxane as produced in SynthesisExample 4 (20.0 mmols in terms of SiH group), 0.18 g of 1-propanol, and0.108 g of distilled water were mixed by stirring them. 48 μl of thesame platinum catalyst solution as in Example 1 was added to theresulting mixture in the same manner as in Example 1. Thus was obtaineda mass of hard plastic foam. The expansion ratio of the plastic foam was5 times.

Comparative Example 1

Two-liquid-type silicone RTV foam (SEF-10, produced by Toray Dow CorningSilicone Co.) was processed in accordance with the instructions for theproduct. Thus was obtained a mass of soft plastic foam, as in Example 1.The expansion ratio of the plastic foam was 10 times, and the diametersof the cells existing in this ranged between 0.5 mm and 0.8 mm.

The characteristic values of the plastic foam samples as obtained inExamples 1 to 6 and Comparative Example 1 are shown in Table 1.

                                      TABLE 1    __________________________________________________________________________              Example 1                    Example 2                         Example 3                               Example 4                                    Example 5    __________________________________________________________________________    Expansion Ratio              10    10   10    10   15    Cell Diameters (mm)              0.2-0.5                    0.2-0.5                         0.2-0.5                               0.3-0.5                                    0.3-0.5    Hardness  5     6    15    10   30    Compassion Strength              Not   Not  Not   2.0  2.1    (Kg/cm2)  measured.                    measured.                         measured.    Coatability    Aqueous   Good. Good.                         Good. Good.                                    Good.    Coating    Composition    Aqueous   Good. Good.                         Good. Good.                                    Good.    Coating    Composition    B    Aqueous   Good. Good.                         Good. Good.                                    Good.    Coating    Composition    C    Adhesiveness              Cohesion                    Cohesion                         Cohesion                               Cohesion                                    Cohesion              failure.                    failure.                         failure.                               failure.                                    failure.              Foam  Foam Foam  Foam Foam              broken.                    broken.                         broken.                               broken.                                    broken.    __________________________________________________________________________                                    Comparative              Example 6                    Example 7                         Example 8                               Example 9                                    Example 1    __________________________________________________________________________    Expansion Ratio              10    10   8     5    10    Cell Diameters (mm)              0.3-0.6                    0.3-0.7                         0.2-0.6                               0.1-0.4                                    0.5-0.8    Hardness  30    32   35    40   6    Compassion Strength              2.3   2.4  2.5   2.6  Not    (Kg/cm2)                        measured.    Coatability    Aqueous   Good. Good.                         Good. Good.                                    Bad.    Coating    Composition    Aqueous   Good. Good.                         Good. Good.                                    Bad.    Coating    Composition    B    Aqueous   Good. Good.                         Good. Good.                                    Bad.    Coating    Composition    C    Adhesiveness              Cohesion                    Cohesion                         Cohesion                               Cohesion                                    Cohesion              failure.                    failure.                         failure.                               failure.                                    failure.              Foam  Foam Foam  Foam Interface              broken.                    broken.                         broken.                               broken.                                    between                                    foam and                                    adhesive                                    broken.    __________________________________________________________________________

The characteristic values of the foam samples as shown in Table 1 weremeasured according to the methods mentioned below.

The hardness was measured on the surface of each sample, using ahardness tester ASKER C Model.

The compression strength was measured in accordance with JIS K7220. (InTable 1, "Not measured" means that the compression strength of thesample was too low and could not be measured herein.)

The coatability was determined by applying each of three aqueous,acrylic coating compositions onto the surface of each sample at roomtemperature, drying it in air and observing the condition of the coatedfilm with the naked eye.

"Good" means that the coated film was good. "Bad" means that the foamsample repelled the coating composition.

The adhesiveness was determined as follows: A two-liquid-type epoxyadhesive (Cemedine Hi-Super) was applied onto an aluminium test piece,which was then attached to the surface of each foam sample. After havingbeen cured at room temperature for 1 hour, the test piece was peeled byhand, whereupon the condition of the peeled surface of the sample wasobserved with the naked eye.

INDUSTRIAL APPLICABILITY

The plastic foam of the present invention can be favorably used invarious applications, for example, for acoustic insulation, heatinsulation, water sealing, air sealing, damping, protection, cushioning,decoration, etc. In particular, it has good weather resistance, andcoating compositions and adhesives can be applied thereto. The foamingresin composition of the present invention, from which the plastic foamis produced, is not toxic and relatively inexpensive. As being able tobe foamed in place by spraying or injection, the composition isespecially useful as sealing materials and interior and exteriormaterials in civil engineering, building and construction, and asmaterials for producing model samples, decorations and accessories.

We claim:
 1. A foaming resin composition comprising;(A) an organiccompound having a carbon-carbon double bond but having no siloxane unitin the molecular skeleton, (B) a compound having an SiH group, and (C) acompound having an OH group.
 2. The foaming resin composition as claimedin claim 1, wherein the molecular skeleton of the organic compound forthe component (A) is composed of at least one or more element selectedfrom carbon, oxygen, hydrogen, nitrogen, sulfur and halogen atoms. 3.The foaming resin composition as claimed in claim 1, wherein themolecular skeleton of the organic compound for the component (A)is apolyether-type, organic polymer skeleton.
 4. The foaming resincomposition as claimed in claim 1, wherein the molecular skeleton of theorganic compound for the component (A) is a phenol-formaldehyde-type,organic polymer skeleton.
 5. The foaming resin composition as claimed inclaim 1, wherein the molecular skeleton of the organic compound for thecomponent (A) is a bisphenol-type skeleton.
 6. The foaming resincomposition as claimed in claim 1, wherein the organic compound for thecomponent (A) has a molecular skeleton of the following formula:##STR1## wherein R¹ represents H or CH₃ ; R⁸ and R⁹ each represent adivalent substituent having from 0 to 6 carbon atoms and composed ofconstitutive element(s) selected from only C, H, N, O, S and halogens; Xand Y each represent a divalent substituent having from 0 to 10 carbonatoms and composed of constitutive element(s) selected from only C, H,N, O, S and halogens; and n, m and l each represent from 1 to
 300. 7.The foaming resin composition as claimed in claim 1, wherein the organiccompound for the component (A) has a molecular skeleton of the followingformula: ##STR2## wherein R¹ represents H or CH₃ ; R¹⁰, R¹¹ and R¹² eachrepresent a divalent substituent having from 0 to 6 carbon atoms andcomposed of constitutive element(s) selected from only C, H, N, O, S andhalogens; X and Y each represent a divalent substituent having from 0 to10 carbon atoms and composed of constitutive element(s) selected fromonly C, H, N, O, S and halogens; and n, m, l and o each represent from 1to
 300. 8. The foaming resin composition as claimed in claim 1, whereinthe organic compound for the component (A) has a molecular skeleton ofthe following formula: ##STR3## wherein R¹ represents H or CH₃ ; R¹³represents a divalent substituent having from 0 to 6 carbon atoms andcomposed of constitutive element(s) selected from only C, H, N, O, S andhalogens; X and Y each represent a divalent substituent having from 0 to10 carbon atoms and composed of constitutive element(s) selected fromonly C, H, N, O, S and halogens; R¹⁴ and R¹⁵ each represent a monovalentsubstituent having from 0 to 10 carbon atoms and composed ofconstitutive element(s) selected from only C, H, N, O, S and halogens;and n and m each represent from 0 to
 4. 9. The foaming resin compositionas claimed in any one of claims 1 to 8, wherein the component (C)comprising an OH group-having compound comprises an organic compoundwith an OH group as directly bonded to the carbon atom therein, and/orwater.
 10. The foaming resin composition as claimed in any one of claims1 to 8, wherein the component (C) comprising an OH group-having compoundcomprises an alcohol and/or water.
 11. A method for producing plasticfoam, comprising foaming and curing a foaming resin composition asclaimed in any one of claims 1 to 8, at 100° C. or lower.
 12. Plasticfoam as produced by foaming and curing a foaming resin composition asclaimed in any one of claims 1 to 8, at 100° C. or lower.
 13. A methodfor producing plastic foam by foaming in place a foaming resincomposition as claimed in any one of claims 1 to 8, wherein thecomponents (A) to (C) of the composition are mixed just before use, thendirectly applied onto the surface of a substrate and foamed thereon. 14.A method for producing plastic foam by foaming a foaming resincomposition as claimed in any one of claims 1 to 8, wherein thecomponents (A) to (C) of the composition are mixed just before use andfoamed through injection.